If you are looking to create video manifestos for your candidates in an election, UnionCloud will allow you to embed their video into the voting web app.

Step 1: Copy the embed code from your video
YouTube:

Vimeo: 
Step 2: Paste into a candidates manifesto
Navigate to your election, click 'Add Standings', an edit the standing with the candidate in.

Then click 'Standing candidates' and edit the candidate:

Then click the 'Source' button on the text editor, and paste in the video embed code: 
